/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: lucky
 * Date: 2022-07-18
 * Time: 14:42
 */
public class BinaryTree {
    static class TreeNode {
        public char val;
        public TreeNode left;
        public TreeNode right;

        public TreeNode(char val) {
            this.val = val;
        }
    }

    /**
     * 创建一个二叉树，返回它的根节点
     *
     * @return
     */

    public TreeNode createTree() {
        TreeNode A = new TreeNode('A');
        TreeNode B = new TreeNode('B');
        TreeNode C = new TreeNode('C');
        TreeNode D = new TreeNode('D');
        TreeNode E = new TreeNode('E');
        TreeNode F = new TreeNode('F');
        TreeNode G = new TreeNode('G');
        TreeNode H = new TreeNode('H');

        A.left = B;
        A.right = C;
        B.left = D;
        B.right = E;
        C.left = F;
        C.right = G;
        E.right = H;
        return A;

    }

    // 前序遍历
    public void preOrder(TreeNode root) {
        if (root == null) return;
        System.out.print(root.val + " ");
        preOrder(root.left);
        preOrder(root.right);

    }

    // 中序遍历
    public void inOrder(TreeNode root) {
        if (root == null)return;
            inOrder(root.left);
            System.out.print(root.val + " ");
            inOrder(root.right);
//        if (root != null) {
//            inOrder(root.left);
//            System.out.printf(root.val + " ");
//            inOrder(root.right);
//        }
    }
        // 后序遍历
    public void postOrder(TreeNode root){
        if(root == null)return;
            postOrder(root.left);
            postOrder(root.right);
            System.out.print(root.val+" ");
//        if(root != null){
//            postOrder(root.left);
//            postOrder(root.right);
//            System.out.printf(root.val+" ");
//        }
        }
}
